Transcript File

Chapter Menu
Lesson 1: Earth’s Oceans
Lesson 2: Ocean Currents
Lesson 3: The Ocean Shore
Lesson 4: Living on the California Coast
Click on a hyperlink to view the corresponding lesson.
10.1 Earth’s Oceans
sea level
ocean floor
bathymetric map
echo sounding
continental shelf
10.1 Earth’s Oceans
Mapping Earth’s Oceans
• Five major oceans: the Pacific Ocean, the
Atlantic Ocean, the Indian Ocean, the
Arctic Ocean, and the Southern Ocean
10.1 Earth’s Oceans
Mapping Earth’s Oceans (cont.)
• Pacific Ocean: largest ocean but decreasing
because surrounded by subduction zones
• Atlantic Ocean: second largest ocean, is
growing larger because of new ocean floor
• Indian Ocean: shallowest ocean
• Arctic Ocean: covered in ice
• Southern Ocean: surrounds Antarctica and
connects the Pacific, Indian, and Atlantic
Oceans
10.1 Earth’s Oceans
Bathymetric Maps
• A map showing the contours of the ocean
floor and its geologic features
10.1 Earth’s Oceans
Echo Sounding
• Water depth can be
determined using
sound waves.
– If the return time is
short, the water is
shallow.
– If the return time is
long, the water is
deep.
10.1 Earth’s Oceans
Ocean Floor
• Scientists use sound waves to make cross
sections of the ocean floor called a
bathymetric profile.
• Identifies continental shelves, continental
slopes and rises, mid-ocean ridges,
trenches, abyssal plains, islands, and
submarine canyons
Ocean Floor
10.1 Earth’s Oceans
Continental Shelf
• An underwater portion of continental crust
that extends from the continental shoreline
and gently slopes towards the deeper parts
of the ocean
• Continental slope: steep slope between the
continent and the deep ocean, contains
deep canyons
• Continental rise: deposits formed between
the continental slope and ocean floor
10.1 Earth’s Oceans
Abyssal Plain and Trenches
• Abyssal plain: an extremely flat plain on
ocean crust covered with thick layers of
sediment
• Trenches: extremely deep underwater
valleys that are subduction zones
10.1 Earth’s Oceans
Mid-Ocean Ridges
• A continuous chain of underwater volcanoes
more than 65,000 km long
• Where tectonic plates
are moving away from
each other and new
ocean floor is created
10.1 Earth’s Oceans
What kind of map is shows the
bottom of the ocean, its contours,
and geologic features?
A contour
B topographic
C bathymetric
D relief
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10.1 Earth’s Oceans
What are the sediment deposits
between the continental slope and
ocean floor called?
A continental rise
B abyssal plain
C trenches
D mid-ocean ridge
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10.1 Earth’s Oceans
Which is the shallowest ocean?
A Pacific
B Atlantic
C Arctic
D Indian
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10.2 Ocean Currents
ocean current
salinity
gyre
10.2 Ocean Currents
Ocean Currents
• Transport water, heat,
nutrients, animals, and
plants from place to
place in the oceans
Ocean Currents
10.2 Ocean Currents
Important Property of Water
• A large amount of heat can be added to or
removed from water before it changes
temperature.
• It takes five times more heat to change the
temperature of an area of water than it
does to change the same area of sand.
10.2 Ocean Currents
Heat Transfer by Oceans
• Amount of energy received from the Sun
varies depending on latitude
– Gained between 30ºN and 30ºS and
at the equator
– Lost at latitudes above 40º
– Amount of ice in polar regions
remains same
– Ocean currents carry heat from the
tropics to the poles
10.2 Ocean Currents
Winds and the Oceans
• Winds are most important force driving the
movement of surface water in the ocean
• Have strongest effect on the location and
movement of the global ocean surface
currents
10.2 Ocean Currents
Coriolis Effect and the Oceans
• The spinning of Earth
causes currents to
move in a clockwise
direction in the
northern hemisphere
and counter-clockwise
in the southern
hemisphere.
10.2 Ocean Currents
Density and Deep Ocean Currents
• Density of water depends on its
temperature and its salt content.
• Salinity is the amount of salt dissolved
in water.
• Different parts of the ocean have different
densities and form deep ocean currents.
10.2 Ocean Currents
Density and Deep Ocean Currents (cont.)
10.2 Ocean Currents
Gyre
• A cycle of currents
10.2 Ocean Currents
Special Currents
• Strongest and deepest currents are on the
western sides of gyres.
• Redistribute heat throughout the oceans
• The Gulf Stream: biggest of these western
boundary currents and is part of the North
Atlantic Gyre
10.2 Ocean Currents
Antarctic Circumpolar Current
• A continuous flow of water that surrounds
land rather than water
• Largest current
• Connects the
Pacific, Atlantic,
and Indian Oceans
10.2 Ocean Currents
El Niño
• Warm water from the
western side of the
Pacific sloshes back
across the ocean due
to weakened trade winds
• Effects are worldwide
and include: droughts,
increased rainfall,
landslides, avalanches,
and flooding
10.2 Ocean Currents
La Niña
• Strong trade winds pull
warm tropical water
across the Pacific
toward Australia
• South American coast
becomes unusually
cold and chilly
10.2 Ocean Currents
What is a cycle of currents called?
A gyre
B salinity
C Coriolis effect
D echo sounding
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10.2 Ocean Currents
D
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Why do beaches get hot while the ocean stays
cool when the sun is shining?
A It takes 5 times more heat to
change the temperature of
an area of sand than it does
the same area of water.
B It takes 5 times more heat to
change the temperature of
an area of water than it does
the same area of sand.
C The ocean has a
high salinity.
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D The ocean has a
low salinity.
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10.2 Ocean Currents
As the salinity of ocean water
increases, what also increases?
A temperature
B speed
C density
D area
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10.3 The Ocean Shore
shore
shoreline
longshore current
longshore drift
rip current
sand
10.3 The Ocean Shore
Shoreline Processes
• The shore is the area of land found between
the lowest water level at low tide and highest
area of land that is affected by storm waves.
• A shoreline is the place where the ocean
meets the land.
• Tides are the alternate rising and falling of
the surface level of the ocean.
How are tides
affected by phases
of the moon?
10.3 The Ocean Shore
Shoreline Processes (cont.)
• Beaches are areas in which sediment is
deposited along the shore.
10.3 The Ocean Shore
Effects of Wind and Waves
• Wind and waves erode larger rocks down
into smaller pieces.
• Shoreline erosion depends on the type of
rock and the intensity of the wind and waves.
• Sea arches are tunnels carved out of rock by
wind and wave erosion.
• Sea stacks form when a sea arch collapses
and one side becomes separated from the
main land formation.
10.3 The Ocean Shore
Effects of Wind and Waves (cont.)
• Deposition occurs when the energy of the
waves is low.
• A baymouth bar is an accumulation of
sediment that completely crosses the
opening of a bay.
• A tombolo is a ridge of sediment that
connects an island to the mainland or
another island.
10.3 The Ocean Shore
Longshore Current and Drift
• The energy driving a narrow current parallel
to the shore is called the longshore current.
• The combination of the movement of sand
by breaking waves and movement of sand
by the longshore current is called
longshore drift.
10.3 The Ocean Shore
Rip Currents
• Swift currents that flow away from the beach
10.3 The Ocean Shore
Human Activity and Beaches
• Artificial structures like jetties, groins, and
breakwaters stop the normal flow of sand,
causing beaches down the shoreline to
become smaller.
• Seawalls also cause
erosion when the energy
that is deflected by the
seawall is redirected on
either side or below it.
10.3 The Ocean Shore
Sand
• Describes rocks that are between
0.0625mm and 2mm.
• Categorized as very coarse, coarse,
medium, fine, and very fine.
10.3 The Ocean Shore
Sand Composition
• White sand: quartz or calcium carbonate
from ground-up shells and coral skeletons
• Black sand: basalt, mica, or magnetite
• Green sand: olivine or feldspar
• Red sand: coral or from iron in volcanic
cinders
10.3 The Ocean Shore
Sand Deposition
• Sand is continuously eroded, transported,
and deposited along the shoreline
• Sorted according to size
• Smaller grains end up
on low-energy beaches
• Larger grains remain on
high-energy beaches
10.3 The Ocean Shore
Sand Deposition (cont.)
10.3 The Ocean Shore
Sand Deposition (cont.)
10.3 The Ocean Shore
If sand is green in color it
might originate from which type
of mineral?
A magnetite
B olivine
C mica
D balsalt
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10.3 The Ocean Shore
Smaller grains of sand can be found
on which type of beach?
A low energy beach
B high energy beach
C beach containing
a jetty
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D beach containing
a seawall
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10.3 The Ocean Shore
What name is given to swift currents
that flow away from the beach?
A longshore currents
B longshore drifts
C surface currents
D rip currents
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10.4 Living on the California Coast
California Current
Davidson Current
habitat
marine
10.4 Living on the
California Coast
Geology of California Coast
• Based on the movement of tectonic plates
• As a result of tectonic activity, coastal
mountain ranges stretch along the entire
state of California.
10.4 Living on the
California Coast
Rocky Beaches
• A few islands in the waters off the California
coast absorb high-energy waves.
• These waves erode the cliffs along the
shoreline, leaving large boulders and cobbles.
10.4 Living on the
California Coast
Tsunamis
• Large sea waves caused by the displacement
of a large amount of water
– Triggered by landslides,
icebergs falling off
glaciers, volcanic
explosions, and
undersea earthquakes
– Sudden rise or drop in
sea level is a warning
sign of a tsunami
10.4 Living on the
California Coast
Currents Along the Coast
• The California Current is a wide,
slow-moving current that travels
southward, bringing cool water down
from northern latitudes.
• The Davidson Current is a narrow, warm
water current that flows north from the tropics
and is stronger in winter than summer.
10.4 Living on the
California Coast
Currents Along the Coast (cont.)
• The two currents collide near Point
Conception, just north of Los Angeles.
10.4 Living on the
California Coast
Hurricanes in California
• Hurricanes are fueled by warm water in
tropical areas.
• The cold water
brought by the
California Current
acts as a
hurricane shield.
10.4 Living on the
California Coast
Sea Life
• The place in which an organism lives is
called its habitat.
• Sea life depends on the types of food
available, the shelter, the moisture, and the
temperature ranges needed for survival.
• In areas where warm and cold water
collide, the ocean is usually full of life.
10.4 Living on the
California Coast
Shore Life
• The intertidal zone is the area of shore
between the lowest low-tide line and the
highest high-tide line.
• The amount of water, exposure to air and
sun varies in the intertidal zone.
10.4 Living on the
California Coast
Humans and the Coast
• Fishing in the waters of the Pacific Ocean is
a big industry.
• Laws determine the number of organisms
that can be removed, the time of year they
can be removed, and the sizes of the
organisms that are removed.
10.4 Living on the
California Coast
Habitat Depletion
• Wetlands and other coastal marsh areas are
habitats for birds, fish, insects, plants, and
marine invertebrates.
• Development leads to habitat and population
reduction of native species.
10.4 Living on the
California Coast
Which current brings cool water
from the north to California?
A California Current
B Davidson Current
C Point Conception
Current
D Los Angeles Current
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Lesson 4 Review
10.4 Living on the
California Coast
A. A Why are there no hurricanes in
B. B California?
A hurricanes do not form
C. C
in the Pacific Ocean
D. D B hurricanes move east
to west
C water off the coast
of California is cold
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D water off the coast
of California is warm
10.4 Living on the
California Coast
A large destructive wave of water is
called a _____.
A tsunami
B surface current
C riptide
D longshore current
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BrainPOP
Click on a hyperlink to view the corresponding feature.
What is formed when a sea arch
collapses and one side becomes
separated from the main land
formation?
A baymouth bar
B tombolo
C gyre
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D sea stack
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How can seawalls cause beach erosion?
A energy is redirected on
either side or below it
B depositing extra sand
along the length of
shoreline
C creating floods that hug
the shoreline and eat
away at the beach
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D eroding away the cliffs
along the shoreline
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Sand spans what size range?
A 0.020 mm – 0.063 mm
B 0.063 mm – 2.0 mm
C 2.0 mm – 5.0 mm
D <0.020 mm
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Why do scientists use echo
soundings?
A measure hurricane
frequency
B measure tsunami
frequency
C measure the depth
of the ocean
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D measure ocean
currents
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In the northern hemisphere, the
Coriolis effect causes ocean currents
to flow in what way?
A west-east
B south-north
C counter-clockwise
D clockwise
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SCI 1.e
Why is the Pacific Ocean getting
smaller?
A increase of glacier
formation
B lava continually rising
the surface
C subduction zones
surround the ocean
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D formation of
mid-ocean ridges
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SCI 4.d
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Which of the following statement is true?
A Currents on the western side
of gyres are important to the
redistribution of heat
throughout the oceans.
B Ocean water gets less salty
when ocean water around it
freezes and forms ice.
C It takes 5 times more heat to
change the temperature of
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an area of sand than it does
that same area of water.
D As the salinity of ocean water
increases, its density decreases.
B
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SCI 2.c
What is a ridge of sediment that
connects an island to the mainland
or another island called?
A playas
B baymouth
C gyre
D tombolo
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SCI 2.a
How is a longshore current described?
A narrow current parallel
to the shore
B swift current that flows
away from the beach
C water breaking through
surf and rushing back
to sea
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D current that flows from
the north bringing cold
water
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SCI 7.f
What type of reference material
show a cross section of the
ocean floor?
A topographic map
B bathymetric profile
C bathymetric map
D echo sounding
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